| Autor: |
Aniket Sanghi, Michael C. Liu, William M. J. Best, Trent J. Dupuy, Robert J. Siverd, Zhoujian Zhang, Spencer A. Hurt, Eugene A. Magnier, Kimberly M. Aller, Niall R. Deacon |
| Jazyk: |
angličtina |
| Rok vydání: |
2023 |
| Předmět: |
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| Zdroj: |
The Astrophysical Journal, Vol 959, Iss 1, p 63 (2023) |
| Druh dokumentu: |
article |
| ISSN: |
1538-4357 |
| DOI: |
10.3847/1538-4357/acff66 |
| Popis: |
We derive the bolometric luminosities ( L _bol ) of 865 field-age and 189 young ultracool dwarfs (spectral types M6–T9, including 40 new discoveries presented here) by directly integrating flux-calibrated optical to mid-infrared (MIR) spectral energy distributions (SEDs). The SEDs consist of low-resolution ( R ∼ 150) near-infrared (NIR; 0.8–2.5 μ m) spectra (including new spectra for 97 objects), optical photometry from the Pan-STARRS1 survey, and MIR photometry from the CatWISE2020 survey and Spitzer/IRAC. Our L _bol calculations benefit from recent advances in parallaxes from Gaia, Spitzer, and UKIRT, as well as new parallaxes for 19 objects from CFHT and Pan-STARRS1 presented here. Coupling our L _bol measurements with a new uniform age analysis for all objects, we estimate substellar masses, radii, surface gravities, and effective temperatures ( T _eff ) using evolutionary models. We construct empirical relationships for L _bol and T _eff as functions of spectral type and absolute magnitude, determine bolometric corrections in optical and infrared bandpasses, and study the correlation between evolutionary model-derived surface gravities and NIR gravity classes. Our sample enables a detailed characterization of BT-Settl and ATMO 2020 atmospheric model systematics as a function of spectral type and position in the NIR color–magnitude diagram. We find the greatest discrepancies between atmospheric and evolutionary model-derived T _eff (up to 800 K) and radii (up to 2.0 R _Jup ) at the M/L spectral type transition boundary. With 1054 objects, this work constitutes the largest sample to date of ultracool dwarfs with determinations of their fundamental parameters. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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